RDX (1,3,5-trinitrohexahydro-s-triazine) is usually manufactured industrially by nitrolysis of hexamethylenetetramine with concentrated nitric acid. This conventional process has the disadvantage that a substantial amount of HMX (cyclotetramethylenetetranitramine) is formed as a by-product, which can exist in several polymorphic forms possessing high impact sensitivity and, unless completely removed, would increase the impact sensitivity of the RDX significantly.
U.S. Pat. No. 3,178,430 discloses a process for preparing RDX without the concurrent production of HMX by reacting a 1,3,5-triacylhexahydro-s-triazine with concentrated nitric acid. As disclosed in the patent, the 1,3,5-triacylhexahydro-s-triazine intermediate, which was reacted with the nitric acid, was previously prepared by the method of the Journal of the American Chemical Society, Vol. 74, pages 5524-5(1952), wherein formaldehyde and the nitrile were reacted in the presence of carbon tetrachloride or other solvents, and the s-triazine formed was separated from the reaction mixture and purified by recrystallization from a solvent.